Mitsubishi Grandis. Manual - part 739

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-207

Code No. P0622: Alternator FR Terminal System

OPERATION

• The energized state of the alternator field coil is 

inputted from the alternator (terminal No. 4) to the 
engine-ECU <M/T> or engine-A/T-ECU <A/T> 
(terminal No. 86).

FUNCTION

• A signal of the power supply duty ratio for the 

alternator field coil is inputted to the engine-ECU 
<M/T> or engine-A/T-ECU <A/T>.

• In response to the signal, the engine-ECU <M/T> 

or engine-A/T-ECU <A/T> detects the alternator 
output current and controls the idling speed 
according to the output current (electric load).

TROUBLE JUDGMENT

Check Condition

• Engine speed is 50 r/min or higher.

Judgment Criterion

• Input voltage from the alternator FR terminal has 

continued to be approximately battery positive 
voltage for 20 seconds.

PROBABLE CAUSE

• Failed alternator

• Open/short circuit in alternator FR terminal circuit 

or loose connector

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

AK305598

4

3

2

1

61
656667686970 717273
74757677787980 8182
8384

858687

8889

62

6364

AB

Engine-ECU <M/T> or
engine-A/T-ECU <A/T>

Alternator

Y-B

Y-B

IC voltage
regulator

B-17

86

3

4 

Alternator circuit

      B-119
(MU802046)

C-112

(MU803804)

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-208

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-119 alternator 
connector

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair or replace.

STEP 2. Perform voltage measurement at B-119 
alternator connector.

• Disconnect connector, and measure at male 

connector side.

• Ignition switch: ON

• Voltage between terminal No. 4 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Go to Step 3 .

STEP 3. Connector check: C-112 engine-ECU 
<M/T> connector or engine-A/T-ECU <A/T> 
connector.

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Repair or replace.

AK300990

2

1

3

4

AC

B-119 (GR)

Connector: B-119

Harness side connector

AK300990

2

1

3

4

AC

B-119 (GR)

Connector: B-119

Harness side connector

AK305617

Connector: C-112 

C-112 (GR)

C-112 (GR)

AB

Harness side connector

<R.H. drive vehicles>

<L.H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-209

STEP 4. Check harness between B-119 (terminal 
No. 4) alternator connector and C-112 (terminal 
No. 86) engine-ECU <M/T> connector or 
engine-A/T-ECU <A/T> connector.

NOTE: Before checking harness, check intermediate 
connector B-17, and repair if necessary.

• Check output line for open/short circuit.

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair.

STEP 5. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES : 

Replace engine-ECU <M/T> or 

engine-A/T-ECU <A/T>.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

STEP 6. Perform voltage measurement at C-112 
engine-ECU <M/T> connector or engine-A/T-ECU 
<A/T> connector.

• Measure engine-ECU <M/T> or engine-A/T-ECU 

<A/T> terminal voltage.

• Engine: Idle after warm-up

• Transmission: Neutral <M/T> or P range <A/T>

• Radiator fan: Inactive

• Voltage between terminal No. 86 and earth.

OK: Switching the headlamps to ON from 
OFF causes the voltage to fall.

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Go to Step 5 .

AK300990

2

1

3

4

AC

B-119 (GR)

Connector: B-119

Harness side connector

AK305617

Connector: C-112 

C-112 (GR)

C-112 (GR)

AB

Harness side connector

<R.H. drive vehicles>

<L.H. drive vehicles>

AK305617

Connector: C-112 

C-112 (GR)

C-112 (GR)

AB

Harness side connector

<R.H. drive vehicles>

<L.H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-210

STEP 7. Check harness between B-119 (terminal 
No. 4) alternator connector and C-112 (terminal 
No. 86) engine-ECU <M/T> connector or 
engine-A/T-ECU <A/T> connector.

NOTE: Before checking harness, check intermediate 
connector B-17, and repair if necessary.

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair.

STEP 8. Check trouble symptom.

Q: Same symptoms regenerated?

YES : 

Replace alternator.

NO : 

Intermittent malfunction (Refer to Group 00 
− How to Use troubleshooting/Inspection 
Service Points 

P.00-5

).

Code No. P0638: Throttle Valve Control Servo Circuit Range/Performance Problem

OPERATION

• Refer to P0657 − Throttle valve control servo 

circuit 

P.13A-218

.

• Refer to P2101 − Throttle valve control servo 

circuit 

P.13A-239

.

FUNCTION

• engine-ECU <M/T> or engine-A/T-ECU <A/T> 

checks the electronic controlled throttle system 
for abnormal conditions.

AK305617

Connector: C-112 

C-112 (GR)

C-112 (GR)

AB

Harness side connector

<R.H. drive vehicles>

<L.H. drive vehicles>

AK300990

2

1

3

4

AC

B-119 (GR)

Connector: B-119

Harness side connector